1. Field of the Invention
The application relates to doors and their methods of manufacturing.
2. Background of the Related Art
Custom overhead doors are typically fabricated with a flush door as a base door. On the base door, hand milled trim boards are fitted to the specified design. While this produces a beautiful product with infinite designs and sizes, it is very time consuming and therefore expensive.
One alternative to the above mentioned door fabrication process is to laminate a sheet of material over the frame. Such a sheet material is typically pre-formed into a design using platens/dies. The benefits of this method is that it is less expensive than assembling hand milled trim.
One problem with using dies and platens is that variations in designs and sizes are limited due to related equipment and storage costs. That is, for designs based on customer-specific tastes, which may be unique, dies or platens must be fabricated or obtained. Once used, the dies or platens would need to be stored for the unlikely event that another customer would have the same design for the same sized door.
More recently, methods have been introduced which attempt to fabricate a sectional-overhead door, such as a garage door, with the use of a CNC (Computer Numerical Control) milling machine. Utilizing a CNC bypasses the need to use dies and platens for creating door designs. However, such'methods, as will be explored, fail to provide a sectional-overhead door having the characteristics and benefits of the disclosed embodiments of the invention.
U.S. Patent Publication No. 2004/0172914 to Barbir, published on May 10, 2007, incorporated herein by reference, discloses a “Seamless Door and Method of Manufacture.” The door is comprised of an MDF (medium density fiber board) core suitable for routering without chip-out, and the core thickness is between 1⅜″ and 2¼″ thick. The door also includes vertical members, a ⅛″ veneer which covers the front and back of the door, and edging which covers the peripheral edges of the door. Once the door is formed, the '914 publication teaches carving a predetermined profile into the front face, back face, or both with a CNC.
One problem associated with the '911 publication is the depth of the veneer. Typical panels in a multi-paneled door are more than one half of an inch deep. By using a CNC on a ⅛′ veneer, router bits will necessarily drill in to the core material, exposing edges between the veneer and the core. Moisture and typical and heating and cooling cycles in an outdoor environment will cause the veneer to pull away from the core. Furthermore, using an MDF core as compared to a foam insulated core will provide the door with relatively poor insulating characteristics and significant extra weight.
U.S. Pat. No. 7,185,468 to Clark et al, granted on Mar. 6, 2007, discloses a “Multi-Layered Fire Door And Method For Making The Same.” Similar to the '914 publication, the '468 publication discloses various layers, including outer veneers which are about ⅛″ thick. As acknowledged in the reference, at column 7, lines 30-50, panels comprised of grooves which are at least a half inch deep could not be manufactured into such doors without penetrating multiple layers of the door.
U.S. Pat. No. 5,782,055 to Crittenden, granted on Jul. 21, 1998, incorporated herein by reference, discloses a “Door Apparatus and Method of Making Door.” The disclosed method comprises the asymmetrical removal of material from the inner portion of the door, inwardly from the perimeter door frame, on both sides of the door. The result is relatively thin webs between relatively thick door portions, as illustrated in FIGS. 2 and 3 of the publication. This provides a serpentine configuration which expands and contracts in response to temperature and/or humidity conditions.
As with the '914 publication, the core of the door in the '055 publication is the material which is routed. Therefore, the core is wood and not an insulating product. Moreover, in the area of the thin webs, the wood is very thin, further decreasing the insulation characteristics of the door.
Another issue with a door manufactured according to the '055 publication is that the thin webs form weak areas in the door. Those areas will fracture under relatively light impact as compared with the rest of the door. Such weakness would be problematic as garage door designs are typically subjected to impacts during a normal lifespan.